In the automobile industry, the system that transmits mechanical power from an engine to an output device is referred to as the transmission. The operation of selecting the various gears in the transmission of an automobile may be manual, automatic or semi-automatic.
Generally, an engine has a flywheel with a bushing located centrally in the flywheel that is capable of receiving a pilot shaft of a transmission. The flywheel and the pilot shaft are configured and designed to have relative motion, and the bushing is configured to provide support between the flywheel and pilot shaft. More particularly, the function of the bushing is to reduce the frictional forces between the flywheel and the pilot shaft. Accordingly, for efficient functioning in the transmission, the bushing must be treated with a lubricant at the time of installation due to the inaccessibility of the bushing. Bushings are generally available as porous bushings or non-porous bushings. Bronze bushings are some of the most commonly-found porous bushings and have tiny air voids capable of receiving lubricant therein.
There are no standard methods available for lubricating a bronze bushing available in a hand tool form. Methods such as wiping a small amount of grease to an inner surface of the bronze bushing or dipping the bronze bushing in a container filled with the lubricant are commonly employed by technicians in the automobile industry such that the porous bronze bushing surface is lubricated but the porous bushing is not impregnated with the lubricant.
There have been some developments in the field of lubricating bronze bushings to improve the lubrication of such bushings. For example, U.S. Pat. No. 5,094,548 to Danly discloses a ‘Composite and self-lubricating bushing’ comprising a monolithic steel body having a machined internal cylindrical surface and a porous bearing layer applied to the surface. The steel body may also include a cavity for storing lubricant and at least one passageway extending between the cavity and the internal cylindrical surface. The bushing may be fabricated by positioning the steel body concentrically over an elastomeric plug, charging the annular cavity between the body and the plug with a sinterable particulate, expanding the elastomeric plug diametrically to compact the particulate, removing the plug and heating the bearing body and compacted particulate. The self-lubricating bushing of the Danly patent involves complex configuration of cavity and passages for storing and circulating the lubricant respectively. This requires sophisticated machining for manufacturing the self-lubricating bushing and therefore increases the cost involved in manufacturing the bushing.
U.S. Publication No. 20060257059 to Masaaki Kubota discloses ‘Self-lubricating bushings, bearings and bearings assemblies’ including lubricant inserts that have central axes that are aligned substantially parallel to the central axes of their respective bushings or bearings. The lubricant inserts present a side edge that is substantially flush with the corresponding bearing surface of the bushing or bearing. The exposed edges of the inserts can extend to the longitudinal edges of the bearing surface of the bushing or bearing. The self lubricating bushing of the Kubota publication contemplates sophisticated machining to make the lubricant insert.
The available art in the current domain have made an attempt to address the issue of lubricating a bushing by making structural modifications to the bushing. Such attempts are complex in nature and involve a high degree of technical skills to operate the same. Accordingly, there remains a need for a device capable of lubricating a bushing in a simple, efficient and cost effective manner without changing the structural configuration of the bushing.